The rights of Eldon G. Samuel III were not violated when he admitted to the murder five years ago in Coeur d’Alene of his dad and brother, the Idaho Supreme Court ruled.

Justices in the ruling filed Wednesday said Samuel signed a Miranda agreement with police before admitting that he used a shotgun and machete to kill his dad, Eldon Jr., and younger brother, Jonathan, at a Coeur d’Alene home owned by St. Vincent DePaul.

The ruling ends a bid by attorneys to overturn the two murder convictions on appeal by arguing that Samuel’s statements to police after the March 2014 murders should have been suppressed because Samuel wasn’t mentally fit to sign a Miranda agreement.

Samuel, 14 at the time of the murders, was sentenced to 15 years for second-degree murder in the death of his father and to life in prison for first degree murder in his brother’s death.

Attorneys also argued that the court abused its discretion when it prohibited evidence of his father’s violent behavior, which may have been the tipping point that resulted in the father’s murder. Attorneys argued at the 2016 jury trial that Samuel had acted in self-defense when he killed his dad by shooting him repeatedly.

In addition, attorneys said First District Judge Benjamin R. Simpson should have allowed Samuel’s mother, Tina, to testify that her son feared his father, and that testimony by expert witnesses should not have been limited.

In statements to police, including his school resource officer who was one of the detectives to interview Samuel, the boy said his father had shot a .45 handgun outside believing a zombie apocalypse had begun. When his father returned inside, he pushed Samuel twice in the chest. Samuel picked up the .45 and shot his dad twice in the stomach. Samuel’s father crawled to his brother’s room, where Samuel shot him three times in the head.

Samuel retrieved a shotgun and shot his brother, who hid under a bed, before beating him repeatedly in the head with a machete until he was quiet. Then Samuel called police.

Justices said the district court made the right decision to limit expert testimony because the expert defense witness was not a licensed psychologist. Justices said despite “inartful statements” by detectives, Samuel’s confession was given voluntarily and that Samuel was mature and mentally sound enough to waive his Miranda rights.

Justices also ruled that the testimony of a physician during the jury trial was outside the scope of the doctor’s expertise, and that although the court did not allow his mother to testify regarding Samuel’s fear of his father, “that error is ultimately harmless,” Chief Justice Roger Burdick wrote.

The Samuels moved to Coeur d’Alene from California a year before the slayings. The three had lived in the small house owned by St. Vincent de Paul North Idaho for about three months and were getting ready to move to permanent housing.

The brothers were registered in the Coeur d’Alene School District. Samuel attended Lakes Middle School, and his brother attended Canfield Middle School.

Samuel is being held at the Idaho Correctional Institution in Orofino. He is eligible for parole in 2032.